Make a prediction about what will happen in the following scenario:

Two bowling balls collide (elastic collision) both have the same mass. If Ball A is moving to the right a 3 m/s and Ball B is moving to the left at 2 m/s. What can be said about the velocity of ball A after the collision?
Ball A will be moving 5 m/s to the right
Ball A will be moving 5 m/s to the left.
Ball A will be moving 2 m/s to the right.
Ball A will be moving 2 m/s to the left.

In an elastic collision, both momentum and kinetic energy are conserved. Since Ball A and Ball B have the same mass, their velocities will exchange after the collision. So, after the collision, Ball A will be moving at 2 m/s to the left. Thus, the correct prediction is: Ball A will be moving 2 m/s to the left.